The invention relates to water heaters, and more particularly to an access door therefore.
Water heaters include an inner storage tank to contain water to be heated, and an outer cylindrical jacket or casing spaced outwardly of the tank. Located within the annular space between the tank and the jacket is a layer of insulating material, typically fiberglass or foamed resin. In a conventional gasfired water heater, the water is heated by a burner located in a compartment beneath the tank. The lower end of the outer jacket is provided with an access opening in order to inspect and maintain the burner and pilot light or ignition device. The access opening is customarily enclosed by a sheet metal panel or door, secured to the jacket by tabs that engage slots in the jacket, as shown in FIGS. 1-4 herein, and described in further detail below. A corner of the panel is cut out to permit entry of the lines leading to the burner, pilot light and thermocouple. Another access door is shown in Ruark U.S. Pat. No. 4,777,933, incorporated herein by reference.
Some water heaters have a power vent for supplying combustion air to and/or exhausting spent combustion products from the burner. The power vent enclosure extends outwardly and forwardly from the jacket and covers a portion of the access opening. The power vent enclosure has a sidewall extending radially outwardly and forwardly from the jacket. The sidewall has an opening therethrough extending radially outwardly and forwardly from the jacket at the access opening. The above noted access door covers the access opening in the jacket, but not the sidewall opening in the power vent enclosure.
The present invention provides an access door covering both the sidewall opening in the power vent enclosure and the remainder of the access opening in the jacket which is not covered by the power vent enclosure. The present access door is particularly simple and cost effective in manufacture, and is forgiving of manufacturing tolerances in fitting to the access opening and sidewall opening. The latter feature is particularly desirable because neither the cylindrical jacket nor the power vent enclosure have a close manufacturing tolerance.
The access door's latching mechanism is also forgiving of manufacturing tolerance, and is particularly simple and efficient. In the preferred embodiment, the access door has top and bottom rearwardly extending walls which are gripped and deflected towards each other to allow clearance of tabs through the access opening in the jacket, whereafter the walls are released and the tabs engage the inner surface of the jacket to hold the door in place. The door has a front wall which is tapered at an angle and extends between the forwardly extending sidewall of the power vent enclosure and the jacket. The front wall of the door has one side engaging the sidewall of the power vent enclosure forwardly of the sidewall opening, and has its distally opposite side engaging the jacket at the other side of the access opening. The sidewall of the power vent enclosure and the jacket act as a stop against the diagonally extending front wall of the access door therebetween, to prevent the door from entering the jacket chamber upon impact.